CO2 packing polymorphism under confinement in cylindrical nanopores

Capillary condensation in cylindrical nanopores

Using grand canonical Monte Carlo simulations, we have explored the phenomenon of capillary condensation (CC) of Ar at the triple temperature inside infinitely long, cylindrical pores. Pores of radius R= 1 nm, 1.7 nm and 2.5 nm have been investigated, using a gas-surface interaction potential parameterized by the well-depth D of the gas on a planar surface made of the same material as that comprising the porous host. For strongly attractive situations, i.e., large D, one or more (depending on R) Ar layers adsorb successively before liquid fills the pore. For very small values of D, in contrast…

A ferroelectric liquid crystal confined in cylindrical nanopores: Reversible smectic layer buckling, enhanced light rotation and extremely fast electro-optically active Goldstone excitations

The orientational and translational order of a thermotropic ferroelectric liquid crystal (2MBOCBC) imbibed in self-organized, parallel, cylindrical pores with radii of 10, 15, or 20 nm in anodic aluminium oxide monoliths (AAO) are explored by high-resolution linear and circular optical birefringence as well as neutron diffraction texture analysis. The results are compared to experiments on the bulk system. The native oxidic pore walls do not provide a stable smectogen wall anchoring. By contrast, a polymeric wall grafting enforcing planar molecular anchoring results in a thermal-history indepe…

Capillary Condensation, Freezing, and Melting in Silica Nanopores: A Sorption Isotherm and Scanning Calorimetry Study on Nitrogen in Mesoporous SBA-15

Condensation, melting and freezing of nitrogen in a powder of mesoporous silica grains (SBA-15) has been studied by combined volumetric sorption isotherm and scanning calorimetry measurements. Within the mean field model of Saam and Cole for vapor condensation in cylindrical pores a liquid nitrogen sorption isotherm is well described by a bimodal pore radius distribution. It encompasses a narrow peak centered at 3.3 nm, typical of tubular mesopores, and a significantly broader peak characteristic of micropores, located at 1 nm. The material condensed in the micropores as well as the first two …

氩预镀MCM-41纳米孔中氦限域的界面工程

Interface Engineering of Helium Confinement in Argon-Preplated MCM-41 Nanopores

本研究通过氩预镀修饰MCM-41纳米孔界面，结合模拟与实验揭示其对氦限域的调控机制，为受限量子流体研究提供了实验约束的微观势能。

How nanoporous silicon-polypyrrole hybrids flex their muscles in aqueous electrolytes: In operando high-resolution x-ray diffraction and electron tomography-based micromechanical computer simulations

Macroscopic strain experiments revealed that Si crystals traversed by parallel, channel-like nanopores functionalized with the muscle polymer polypyrrole exhibit large and reversible electrochemo-mechanical actuation in aqueous electrolytes. On the microscopical level this system still bears open questions, as to how the electrochemical expansion and contraction of PPy acts on to np-Si pore walls and how the collective motorics of the pore array emerges from the single-nanopore behavior. An analysis of in operando X-ray diffraction experiments with micromechanical finite element simulations, b…

Confinement Effects on the Crystalline Features of Poly(9,9-dioctylfluorene)

Typical device architectures in polymer-based optoelectronic devices, such as field effect transistors organic light emitting diodes and photovoltaic cells include sub-100 nm semiconducting polymer thin-film active layers, whose microstructure is likely to be subject to finite-size effects. The aim of this study was to investigate effect of the two-dimensional spatial confinement on the internal structure of the semiconducting polymer poly(9,9-dioctylfluorene) (PFO). PFO melts were confined inside the cylindrical nanopores of anodic aluminium oxide (AAO) templates and crystallized via two crys…